Manufacture of oxygen.



" omen snares PATENT HEINRICH KBIEGSHEIIYI, 01* NEW YORK, N. Y.,'ASSIGNOB TO THE PERMUTIT COMPANY,

'- OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

MANUFACTURE OF OXYGEN.

No Drawing.

have invented certain new and useful Improvements in ManufactureofOxygen, of

which the following is a specification.

This invention relates to the manufacture of oxygen; and it comprises amethod of preparing oxygen with the aid of chlorin,

which may be waste chlorin from any source,

wherein such chlorin is absorbed in lime or lime water or any suitablealkaline material to make a corresponding hypochlorite, and thehypochlorite so made, or a hypochlorite made in any other way, in theform of a water solution is brought into contact with an exchangesilicate, or reactive zeolite, containing a catalytic oxid, such asmanganese oxid, nickel oxid, cobalt oxid, copper oxid, etc., to cause acatalytic decomposition with evolution of oxygen and formation of achlorid corresponding to the hypochlorite used; all as more fullyhereinafter set forth and as claimed.

The problem of obtaining oxygen ina cheap and convenient way is one ofgreat industrial-importance for many purposes. A cheap, convenient andproductive source of oxygen is, for example,'highly des1rable inconnection with autogeneous welding and many other processes wherein theoxygen of air is, so to speak, in too highly diluted a condition toserve. The many methods which have been proposed for producing oxygen bydecomposition of highly oxygenated compounds, such as chlorates,manganese dioxid, barium peroxid, plumbates, etc., by heat are allexpensive and inconvenient and have found little foothold in the arts.Producing oxygen from liquid air by distillation processes requires acumbrous and expensive plant.

For technical purposes a much better and more convenient source is thatafforded by the catalytic decomposition of hypochlorites; whichhypochlorites may be, and advantageously are, obtained by the absorptionof waste chlorin from any source in such an Specification of LettersPatent.

ratentea'se t. 14 rats.

Application filed November 17, 1914. Serial No. 872,526.

alkaline material as milk of lime. Hypochlorites in solution in contactwith certain metallic oxids split up smoothly and completely into thecorresponding chlorids and free oxygen; calcium hypochlorite (orbleaching powder), for example, when contacted in solution with cobaltoxid, yielding calcium chlorid and oxygen which escapes in the gaseousform. The reaction is purely catalytic, very small quantities of oxidssufficing to decompose relatively large amounts of hypochlorites and theoxids being found apparently unchanged at the end of the action. But thespeed and completeness of the action depend very materially on thephysical form of the oxid and upon the circumstances; upon the way inwhich the reaction mixture and the catalyst are brought together. I

I have found that a very advantageous type of action for the presentpurposes is attained by using a compound catalyst formed from suchcatalytic bodies carried in what are known as exchange silicates orzeolites; the materials which are used for purifying water and otherliquids by exchanging contained bases for those contained in suchliquid. These silicates, which may be either natural or artificial butare more commonly of artificial origin, usually contain silica, aluminaand alkali in combination and in a hydrated condition. The alkali may bepotash or soda, or both. More rarely other amphoteric or weakly basicoxids, such as tin oxid, titanium oxid, etc., are used to replace partor all of thealumina. When artificially made, the zeolites may beprepared' granules the latter take up the lime and give up sodium orpotassium which goes into solution as a salt of the acid formerlycomgranules are restored to their original state,

ready for reuse. I have found that by impregnating this exchangematerial with salts of the catalytic metals-I obtain a granular compoundcatalyst eminently suited for the stated purpose. For example, granulesof one of the zeolites may be treated with a solution of sulfate,chlorid or nitrate of cobalt and after a time, to allow reaction to takeplace, the. excess of the solution may be removed. Corresponding saltsof nickel, manganese, copper or lead may be used; or their mixtures. ButI find on the whole the cobalt, nickel and manganese salts to be bestadapted. This granular compound catalytic material may be brought intocontact with the hypochlorite solution, which is advantageously quitestrong, in any suitable apparatus. The hypochlorite solution may bepreviously filtered. A relatively small quantity of catalyst suliices toproduce a strong and vigorous evolution of oxygen which may be led offand collected, and which may be washed and dried, if desired. Thedecomposition of the hypochlorite is quantitative, an amount of oxygencorresponding to the amount of chlorin present being evolved. Theparticles of contact material may be enveloped by the gas bubbles to anextent preventing the desired intimate mixture of such material with theliquid. It is therefore advantageous to move the contact materialintermittently or continuously by stirring or shaking to promoteintimate contact of the prepared silicates and to prevent enveloping ofthe particles by gas bubbles. Toward the end of the action, the

mixture may advantageously be raised in temperature somewhat. Aftercompletion of the action the solution of calcium chlorid or otherchlorid produced by decomposition of the hypochlorite may be removedfrom the mass of granules of compound catalyst, and such catalyst isthen ready for reuse. The solution may be caused to flow in continuousstream through a sufficiently thick layer of the silicates. In thismethod the compounds of the catalytic metals are presented for action ina state of the finest possible subdivision and have a maximum activity.This high activity may also probably be, in part at least, attributed toan influence of the carrier; the exchange silicate. The compound contactbody does not lose in activity by repeated use. No disadvantageousby-products are formed and there is no waste of the catalyst. Thereaction, or the greater part of it, may take place at the ordinarytemperature. Ordinary bleachinto milk of lime as long as absorptiontakes place, the fluid obtained,uwith or without filtration, iscontacted with the described compound contact body. Caustic sodasolution and other alkaline solutions may also be used.

What I claim is p 1. The process of making oxygen which comprisescontacting ahypochlorite solution with an exchange silicate containing acatalytic metal compound and collecting the oxygen produced.

2. The process of making oxygen which comprises contacting ahypochlorite solution with an exchange silicate containing a cobaltcompound and collecting the oxygen produced.

3. The process of making oxygen which comprises impregnating an exchangesilicate. with a solution of a salt of a catalytic metal, removing theexcess of the solution, contacting the impregnated silicate with ahypochlorite solution and collecting the oxygen produced.

4. The process of making oxygen which comprises impregnating an exchangesilicate with a solution of a cobalt salt, removing the excess ofsolution, contactingthe impregnated silicate with a hypochloritesolution and collecting the oxygen produced.

5. The process of producing oxygen which comprises absorbing chlorin inan alkaline liquid, contacting such liquid with an exchange silicatecontaining a compound of a catalytic metal and collecting the oxygenproduced.

6. The process of producing-oxygen which comprises absorbing chlorin inmilk of lime,

contacting the liquid obtained with an excomprises absorbing chlorin inmilk of lime to produce a liquid containing hypochlorite, impregnatingan exchange silicate with a salt of a catalytic metal, contacting theimpregnated silicate with the liquid and collecting the oxygen produced.

9. The'process of making oxygen which comprises contacting ahypochlorite solution with an exchange silicate containing a catature inthe presence of two subscribing witlytic compound, and agitating thesilicate nesses.

to quickly remove gas bubbles and to pro- HEINRICH KRIEGSHEIM. moteintimate contact of the liquid with the Witnesses: 5 silicate.

MAURICE P. STACK, In testimony Whereof,.-I afiix my .signa- ALFRED M.HOUGHTON.

